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A1-14207(1)
2/2
NOTE:
.
Self-recording
means "Record the audio signal and play
back the just-recorded portion".
2-3-3. BIAS LEVEL ADJ.
[Al
Measuring Point Measuring Equipment
ADJ, Condition
TP201(HOT)
Oscilloscope
REC (SP) mode
TP202 (GND)
AC voltmeter
Blank tape
ADJ. Location
ADJ. Value
VR201 (BIAS)
23 mVrms
1.
Load the
VCR
with a blank tape and
select the SP record
mode without all incoming signal.
2.
After confirming
on the oscilloscope that a 70 kHz sine
wave is being output, adjust VR201 (BIAS) sothatthe
AC
L
voltmeter's reading is23
mVrms.
[B]
Measuring Point I Measuring Equipment
IADJ, Condition
AUDIO OUTPUT
Oscilloscope
Self-recording
terminal
AC voltmeter
(SP mode
(EURO-AV pin 3: Standard audio signal
Blank tape)
Lch)
generator (SG:signal
-33.8 dBs, 1 kHz
-33.8 dBs, 10 kHz)
ADJ. Location
ADJ. Value
VR201 (BIAS)
-4 dB - +4dB
between 400 kHz and 10 kH;
1.
Connectthestandard
audio signal generatortotheAUDIO
INPUT terminal (EURO-AV pin6: Lch).
2.
Set the standard audio signal generator's output level to
-33.8 dBs.
3.
Set the standard audio signal generator's frequency to
400 Hz and then 10 kHz. Record each of these frequency
signals.
4.
Play back each of the just-recorded
portion.
5.
Confirm that the 10 kHz level on AC voltmeter's reading is
from -4 dB to +4 dB, compared with 400 Hz level.
6.
If the 10 kHz level is less than -4 dB below 400 Hz level or
more than +4 dB above 400 Hz level, Rotate VR201 (BIAS)
slightly to adjust it.
7.
Repeat steps 3 through 6 if necessary.
–13–
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